智能车辆路径跟踪横向混合控制器设计

Mixed Lateral Controller Design for Path Tracking of Intelligent Vehicle

智能车辆路径跟踪横向控制系统中存在较大初始偏差条件下,单一控制策略很难同时满足智能车辆系统对鲁棒性和跟踪精度的要求,为此,设计了一种由模型预测控制(MPC)算法和纯追踪(PP)控制算法组成的路径跟踪横向混合控制器。在初始阶段,横向偏差较大,运用PP控制算法控制车辆;当横向偏差较小且前轮转角变化量满足MPC控制算法的约束时,切换到MPC控制算法。针对该横向混合控制器进行仿真分析和实车试验验证,结果表明:存在较大初始偏差条件下,该控制器在不同车速下均能够快速纠正路径偏差,且能保证路径跟踪过程中的横向偏差范围在±0. 1 m,方向偏差范围在±4°,具有较强的鲁棒性和较高的跟踪精度。

Considering the difficulty of meeting the performance requirements of the intelligent vehicle path tracking under a big tracking error condition with a single control strategy,a mixed switching lateral controller based on model predictive control(MPC)algorithm and pure pursuit(PP)control algorithm is designed.Considering the PP control algorithm has strong robustness to correct the error quickly,the path tracking system is controlled by the PP control algorithm at first where the initial error is huge.When the lateral is small and the front wheel angle meets the constraint of MPC control algorithm,the path tracking system is controlled by the MPC control algorithm.When the initial lateral is1m and the initial direction error is-9°,the mixed lateral control system is simulated at different speed respectively.The vehicle test is carried out at the speed of10m/s.It is showed by results that the controller designed can correct the error quickly under different longitudinal velocity.The lateral error ranges±0.1m and the direction error is less than4°,which means that the controller has a strong robustness and high tracking accuracy.